1. Field of the Invention
The present invention relates to an oscillometric blood pressure measuring apparatus which detects a pulse wave of a living subject and enables a doctor to make a diagnosis based on the waveform of the pulse wave.
2. Related Art Statement
The waveform of a pulse wave produced from an artery of a living body or subject provides useful information reflecting the condition of blood circulation of the subject. There have been proposed various diagnosing apparatus which analyze the waveform of a pulse wave of a subject and make a diagnosis on the circulatory organ of the subject based on the analyzed results.
Generally, the conventional diagnosing apparatus employ (a) an arterial catheter which is invasively inserted into an artery of a subject, and (b) a pressure sensor for directly detecting a pulse wave from inside the artery. Additionally, U.S. Pat. No. 5,238,000 discloses a pressure pulse wave sensor which is pressed on the skin of a subject for indirectly detecting a pressure pulse wave produced from an artery under the skin.
In the first, direct pulse wave detecting technique, a skilled doctor is needed to carry out the insertion of the catheter into the artery, and the arterial invasion due to the catheter insertion gives serious stress to the subject. In the second, indirect pulse wave detecting technique, an exclusive pressure pulse wave sensor is needed, so that the overall apparatus becomes complicated and expensive. Also, it is more or less cumbersome to set the sensor on the skin of the subject.